Torque Shop

I read with alarm and dismay about how Star Trek actor Anton Yelchin died last month when his Jeep Grand Cherokee rolled down a slope and crushed him. How safe is it to leave a car's transmission in Park position, without engaging the parking brakes?

If there is no mechanical flaw in the car, it should not roll away in Park. But if the gearbox is defective, leaving the lever in "P" may not lock the vehicle in position.

There are instances when a transmission's Drive or Reverse does not engage either. This may be a linkage problem.

The same thing could happen in Park, rare as it may be.

The United States National Highway Traffic Safety Administration had reported in February that last year's model of the Jeep Grand Cherokee could move even when the transmission is in Park. This mechanical problem has led to more than 100 crashes, it said.

So to be safe, it would be best to engage your car's parking brakes and turn off the engine - even if you are leaving the vehicle momentarily.

And if on a slope, you might want to take the extra precaution of pointing the wheels towards the curb. So that if the vehicle does roll away, it will hit the curb and come to a halt, minimising damage.

SHREEJIT CHANGAROTH

A version of this article appeared in the print edition of The Straits Times on July 16, 2016, with the headline 'Torque Shop'. Print Edition | Subscribe